The energy consumption of the door closing process was decomposed into six subsystems, which include door weight, hinge, checklink, latch, weather strip seal and airbinding effect. The working principle of each subsystem was analysed and then the mathematical model of each subsystem in the door closing process was established, respectively. The energy consumption of the door was calculated programmatically via an Excelbased software using VBA programming language. The energy consumption of different subsystems of a production vehicle door was measured to verify the accuracy of the calculation software developed. The proposed research provided not only the theoretical basis for the future door closing energy research, but also an interactive method and system, and improved the efficiency of vehicle door design effectively.